Telephone instrument.



No. 684,963. Pateniedfjct. 22, l90l.

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TELEPHoNE INSTRUMENT.

(Application filed Nov. 5, 1900.)

(No Model.)

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UNITED STATES PATENT OFFICE.

WILLIS lV. VASHBURN, OF CHICAGO, ILLINOIS.

TE'LEPHONE INSTRUMENT.

SPECIFICATION forming part of Letters Patent No. 684,963, dated October 22, 1901.

Application filed November 5, 1900. Serial No. 35,487. (No model.)

T0 all whom t may concern:

Beit known that I, WILLIS W. WASHBURN, a citizen of the United States, residin gat Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Telephone Instruments, (Case No. 1,) of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to telephone instruments; and its principal object is to provide a device of this kind which can be used either as a transmitter or a receiver, which can be constructed at a very low cost, and will at the same time involve simplicity of operation and construction and eiiiciency of action.

In the accompanying drawings, Figure 1 is a longitudinal section of a telephone instrument embodying my invention. Fig. 2 is a view, partly in elevation and partly in longitudinal section, of the same in a position at right angles transversely to the position in Fig. 1. Fig. 3 is a transverse section taken on line 3 3 in Fig. 2.

In the telephone instrument illustrated a 4 metallic cylindric shell 1, preferably brass, is

inclosed within an insulating cylindric shell 2, preferably composed of hard rubber or vulcanite. A metallic cup 3, also desirably composed of brass, is secured, as by soldering, to the lower end of the cylindrio shell 1, this cup 3 having an annular shoulder 4, upon which the cylindric shell 2 rests. The upper end of the metallic shell l is threaded, and a cap 5, of insulating material, such as vulcanite, is screwed upon the outer end of the shell 1. A diaphragm 6 is arranged across the lower end of the cup 3, and a mouth or ear piece 7 is iitted to the lower end of the cup 3, as by having a ange 8 adapted to surround the lower end of the cup 3 and screwthreaded, so as to correspond with screwthreads on said cup 3. The diaphragm 6 is iitted between the abutting surfaces of the cup 3 and the mouthpiece 7. A permanent magnet 9 is confined within the metallic shell 1, the said magnet being a horseshoe-magnet and havingits opposite sides extended lengthwise of the shell 1 and the ends thereof situated near the lower end of said shell. One

' nular space intervenes between the two.

of the ends of said magnet 9 is provided with a pole-piece 10, composed of soft iron and extended downwardly, so that its end lies close to the diaphragm 6. This pole-piece 10 has its lower end made cylindric in form and is arranged so as to lie behind the central portion of the diaphragm 6. The other end of the magnet 9 is provided with a pole-piece 11, which is also composed of soft iron and is eX- tended substantially to the diaphragm 6. The pole-piece 11 is tubular in shape and incloses the pole-piece 10, so that a small an- A coil 12 of Wire is arranged about the .polepiece 10 and within the pole-piece 11. The ends of the coil 12 are led out of the polepiece 1l through small apertures formed in a piece ot insulating material 13, which is iitted into a longitudinal slot formed in the polepiece 1l. The ends of the wires led out through the insulating-strip 13 are connected with binding-posts 14 14. The pole-piece 1l has its upper portion screw-threaded, and this portion tit-s and screws into a correspondinglyscrew-threaded portion of the metallic cup 3. A set-screw l5 is screwed into one side of the eu p 3, so as to bind against the screw-threaded portion of the pole-piece 1l.

The telephone instrument as thus constructed possesses high etticiency and an exceedingly-sensitive action and at the same time has such mechanical features that it can be readily and easily put together and taken apart and when put together will be very strong and durable.

What I claim as my invention is 1. In a telephone instrument, the combination with an inclosing shell or casing having a cup-shaped metallic portion, of a horseshoe-magnet arranged within said shell or casing and having one of its ends provided with a solid pole-piece and the other provided with an annular pole-piece inclosing the solid pole-piece, the said annular pole-piece being screw-threaded and the said cup-shaped portion of the inclosin g casin g being correspondingl y threaded so that the pole-piece can be screwed into the cup-shaped portion to hold the magnet in position in the instrument.

2. In a telephone instrument, the combination of a metallic cylindric shell, an inroo' end, the said annular pole-piece having a sulating-shell arranged outside of the metallic shell, a cup-shaped metallic portion secured to the said cylindric shell and having a screw-threaded socket below its connection with said cylindric shell, a cap composed of insulating material and fitted upon the outer end of the metallic shell, an `insulating mouth or ear piece fitted to the cup-shaped portion, a diaphragm arranged Within the said mouth or ear piece, a permanent magnet arranged Within the metallic shell and having one of its ends provided with an annular pole-piece adapted to inclose the pole-piece of the other screw-threaded portion adapted to [it Within the screw-threaded socket of the said cup, a

coil of wire arranged between the pole-pieces,

an insulating-strip arranged in a slot in an annular pole piece and having apertures through which the Wires Within said polepiece can be extended, and binding-posts to which said wires are connected, substantially as described.

In a telephone instrument, the combination with a horseshoe-magnet having its ends provided with longitudinally-extending pole-pieces, one of which is tubular in form and is arranged to inclose the other, of an inclosing shell or casing for said magnet, the said shell or casing being arranged to engage the tubular pole-piece so as to hold thc niagnet in position in such shell or easing, substantially as set forth.

4. In a telephone instrument, the combination with an inelosing shell or casing having a screw-threaded socket, of a horseshoemagnet having its ends provided with polepieces, one of which is tubular in form and is arranged to inclose the other pole-piece and is provided with a threaded portion adapted to t into the screw-threaded portion of the shell or casing, substantially as set forth.

5. In a telephone instrument, the combination of atubular metallic shell having one of its ends screw-threaded, a cup-shaped structure having its smaller end secured to said metallic shell, an insulating-shell inclosing the metallic shell, a cap having a sereW- threaded portion adapted to fit the threaded portion of said metallic shell and holding the insulatingshell against the cup-shaped structure, a mouth or ear piece fitted to the eupshaped structure, and a diaphragm interposed between the ear or month piece and the ilaring end of the cup-shaped structure, substam tially as described.

In witness whereof I hereunto subscribe my name this Ist day of November, A. D. 1900.

WILLIS IV. WASlIlzlURN. 1Witnesses:

A. MILLER BELFIELD, HARVEY L. IIANsoN. 

